This invention relates to the product and method of making bellows, and more particularly to the method of making bellows from thermoplastic sheet material.
Heretofore, bellows, particularly the type which are incorporated in a breathing testing machine or spirometer have been made entirely of rubber. In a conventional process for making rubber bellows, a model of solid material made in the shape of a bellows is repeatedly dipped in a bath of molten latex in order to build up a succession of laminations of latex until the desired thickness of the rubber bellows is attained.
Because of the relatively high cost of rubber bellows, such bellows are used repeatedly in breathing machines or spirometers, thus accumulating bacteria within the bellows from different patients, to create a highly unsanitary condition.